It will be several weeks before toxicology tests that could reveal what killed Whitney Houston will be available, but according to new reports, the singer had visibly fallen off the wagon in the days before her death on Saturday.

Houston, 48, had famously struggled with drug and alcohol addiction for more than a decade, and while friends and confidants have said in numerous interviews this week that the singer had been free of illegal drug use lately, CNN reported on Wednesday that the singer had been drinking "considerable" amounts of alcohol just days before she was found unconscious in her hotel bathtub.

The news network claimed that an unnamed source said Houston ordered drinks before 10 a.m. last Wednesday and Thursday from the bars in the lobby and pool area of the Beverly Hilton hotel. Guests reportedly overheard Houston loudly complaining about the drinks, with the source claiming the singer accused bartenders of "watering down" and "putting too much ice" in her beverages.

The unnamed source also said that other guests expressed concern over Houston's erratic behavior and disheveled appearance, which included mismatched clothing. The once chart-topping diva was reportedly alone for some of the time, but was also seen drinking with her entourage and an unidentified male companion on both days.

Houston was also spotted drinking at the pool on the morning of her death, though the source said witnesses did not describe her behavior as erratic on that day.

While a potentially deadly mixture of prescription drugs and alcohol were initially fingered as the possible cause of death, the Los Angeles County coroner's office has withheld announcing a definitive cause pending the results of the toxicology tests. In the meantime, subpoenas have been issued seeking Houston's medical records and prescriptions.

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